%0 Journal Article
%T Significant Association of Streptococcus bovis with Malignant Gastrointestinal Diseases
%A Salah Shanan
%A Samia A. Gumaa
%A Gunnar Sandstr£¿m
%A Hadi Abd
%J International Journal of Microbiology
%D 2011
%I Hindawi Publishing Corporation
%R 10.1155/2011/792019
%X Streptococcus bovis is a Gram-positive bacterium causing serious human infections, including endocarditis and bacteremia, and is usually associated with underlying disease. The aims of the current study were to compare prevalence of the bacterium associated with malignant and nonmalignant gastrointestinal diseases and to determine the susceptibility of the isolated strains to different antimicrobial agents. The result showed that the prevalence of S. bovis in stool specimens from patients with malignant or with nonmalignant gastrointestinal diseases was statistically significant. This result may support the idea that there is correlation between S. bovis and the malignant gastrointestinal diseases. 1. Introduction Several species of bacteria have been linked to chronic infections of colon and have been shown to increase the risk of colon cancer. Streptococcus bovis has been evaluated as one of the possible etiologic agents for colorectal cancer [1]. S. bovis is a Gram-positive bacterium, which is considered as a normal inhabitant of the human gastrointestinal tract but is less frequently present than other Streptococcus species [2]. Whatever, S. bovis has been shown to be an increased cause of endocarditis and bacteraemia and found to be associated with gastrointestinal diseases [3¨C6] or with the colorectal cancer [7¨C10]. Although a number of bacteria have been associated with cancer, their possible role in carcinogenesis is unclear. In some cases Helicobacter pylori may cause stomach cancer [11, 12] since animal models have demonstrated Koch¡¯s third and fourth postulates for the role of H. pylori in the causation of stomach cancer [13]. Moreover, it has been found also that Salmonella typhi is associated with gallbladder cancer [14] and Escherichia coli with Crohn's disease as well as colon cancer [15, 16]. McCoy and Mason first reported a case of the association between streptococcal endocarditis and colon cancer in 1951 [7]. Many studies have examined the presence of S. bovis in stool samples obtained from patients with colorectal cancer to find a relationship between this bacterium and the risk of colorectal cancer. In 1977, Klein et al. found a significantly strong association of S. bovis in stool samples of patients with colon cancer compared with healthy controls and patients with nonmalignant gastrointestinal disease [17]. This important finding was confirmed in later studies [18¨C20]. In contrast, other studies did not find any significant association between faecal S. bovis and human colorectal cancer [21¨C24]. The aims of the current study were
%U http://www.hindawi.com/journals/ijmicro/2011/792019/